As a related-art interior permanent magnet motor, in Patent Literature 1, there is disclosed an interior permanent magnet motor in which a plurality of slits are formed on a radially outer side of a rotor with respect to magnet insertion holes. In the interior permanent magnet motor, a harmonic component of a magnetic-flux density waveform is reduced due to a function of the slit so that a harmonic of an inducted voltage and a clogging torque are reduced, thereby being capable of reducing noise and vibration.